Nest E Wiring Help

Reply

  #1  
Old 12-20-17, 05:09 PM
Member
Thread Starter
Join Date: Dec 2017
Location: United States
Posts: 2
Received 0 Votes on 0 Posts
Nest E Wiring Help

Hi,
I stumbled across this forum while searching the net for information on wiring a Nest-E thermostat. The website says my system is compatible, but recommends professional installation. I'm not interested in paying $100 for someone to come out and hook up a couple of wires, so I'm hoping I can find some cheaper information.
My old thermostat is a White-Rodgers 1F95EZ-0671. It has the following connections:
C - A separate light blue wire (builder did some redneck engineering to get a C wire. Ran a 2nd cable)
RH & RC - Jumpered and a red wire connected to RC
O/B - Light blue wire
W/E - Brown wire
W2 - White wire
G - Green wire
Y - Yellow wire

The Nest-E has the following connections:
Y1 - Yellow wire should go here
G - Green wire should go here
R - Red wire should go here
W1 - ??? Brown or white (or both)?
C - Separate blue wire goes here
*OB - Blue wire goes here
It all seems pretty straightforward except for the brown and white wires. It's not clear where they should go.
The Nest-E manual says that if I have a W2 wire, I can connect it to the *OB, but a wire is already there.
Any suggestions on how I should connect those wires? Thanks.
 
Sponsored Links
  #2  
Old 12-20-17, 05:19 PM
Member
Thread Starter
Join Date: Dec 2017
Location: United States
Posts: 2
Received 0 Votes on 0 Posts
UPDATE: I pulled the cover on the air handler to see how it is wired. It has the following connections on the circuit board:
C - blue wire
R - a black wire which is connected to a red wire
G - green wire
Y/Y2 - yellow wire
O - brown wire
W1 - black wire, but I couldn't figure out where it is connected.
W2 - no connection
Y1 - no connection
L - no connection
This wiring leads me to believe that I don't have an AUX heating unit. The system was replaced several years ago. The original system did have Aux heating, so I'm thinking I have some leftover wiring from that.
 
  #3  
Old 12-20-17, 05:21 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,372
Received 10 Votes on 8 Posts
It looks like you have solved your own question.
 
  #4  
Old 12-20-17, 05:33 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,668
Received 340 Votes on 318 Posts
The nest will support AUX heat on W2. Emergency heat on the *

White on W2 and cap off brown or use the * for brown and program it for E heat.
When the nest is in heat pump mode.... W1 is disabled.

You had a white on W at the stat. It must change to black thru a splice.
It is VERY confusing when the stat colors don't match the colors at the air handler. I would follow the colors at the stat.

You can right click on this diagram and select "view picture" for a larger view.
These are not the same colors but the descriptions are.
Name:  nest temp.JPG
Views: 14000
Size:  59.0 KB

C - A separate light blue wire ------> C
RH & RC - Jumpered and a red wire connected to RC -------> Rh
O/B - Light blue wire -------------> O/B
W/E - Brown wire ---------------> *
W2 - White wire -----------------> W2
G - Green wire -------------------> G
Y - Yellow wire ------------------> Y1
 
  #5  
Old 12-20-17, 05:58 PM
Houston204's Avatar
Forum Topic Moderator
Join Date: Oct 2009
Location: Texas
Posts: 7,372
Received 10 Votes on 8 Posts
I wonder why the new Nest E thermostat would be less capable.

https://www.google.com/search?q=Nest...b3kZ7pPyocYEM:
 
  #6  
Old 12-20-17, 06:06 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 52,668
Received 340 Votes on 318 Posts
That looks like a stripped down version for those that don't need all the connections. No emergency heat support.

So for the nest E

C - A separate light blue wire ------> C
RH & RC - Jumpered and a red wire connected to RC -------> R
O/B - Light blue wire ------------->* O/B
W/E - Brown wire ---------------> no connection
W2 - White wire -----------------> W1
G - Green wire -------------------> G
Y - Yellow wire ------------------> Y1
 

Last edited by PJmax; 12-20-17 at 06:21 PM.
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: